Role of mTOR signalling in the control of translation initiation and elongation by nutrients.

摘要: Protein synthesis requires nutrients both as precursors (amino acids) and a source of energy, since this process consumes high proportion cellular metabolic energy. Recent work has shown that types directly influence the activities components translational machinery in mammalian cells. Amino acids positively regulate signalling through target rapamycin (mTOR) pathway, although degree dependency on external amino varies between cell types. mTOR modulates several key involved mRNA translation, particular (via repressor proteins) cap-binding initiation factor eIF4E, ribosomal protein S6 kinases, elongation eEF2. The branched-chain acid leucine is most effective one It currently unclear how cells sense prevailing levels, may involve intracellular acids. Cellular ATP levels can also activity. some translation factors are modulated by mTOR-independent mechanisms. Examples include regulation eEF2 energy which be controlled via AMP-activated kinase, activity guanine nucleotide- exchange eIF2B, fuels.